1. Field of the Invention
The present invention relates to a vehicle surroundings monitoring apparatus which recognizes an object affecting the travel of a vehicle.
2. Related Background Art
Conventionally, as this type of vehicle surroundings monitoring apparatus, there has been suggested a display processor which extracts an object such as a pedestrian likely to collide with a vehicle from an image of vehicle surroundings taken by an infrared camera and visually provides a vehicle driver with the information (for example, refer to Japanese Patent Laid-Open No. Hei 11(1999)-328364).
This apparatus searches for a high-luminance area by binarizing an infrared image and determines whether the high-luminance area represents a pedestrian's head from head determination conditions such as a centroid position, an area ratio, and a net area of the high-luminance area in the infrared image. After determining the area of the pedestrian's head, the apparatus then sets an area including a pedestrian's body and displays these areas separately from other areas. Thereby, the position of the entire pedestrian's body in the infrared image is identified and the information is displayed to the vehicle driver for visual aid.
For example, when binarization is made for an infrared image of a tree existing around the vehicle, however, the height (the length in the vertical direction) of the high-luminance area may be almost the same as the pedestrian's height in some cases under the influence of leaves of the tree. Therefore, the tree may satisfy the above head determination conditions of the centroid position, the area ratio, and the net area in the infrared image and be incorrectly determined to be a pedestrian.
As described above, the conventional vehicle surroundings monitoring apparatus often cannot correctly distinguish and determine the object type.
In view of the above problem, it is an object of the present invention to provide a vehicle surroundings monitoring apparatus capable of distinguishing and determining the object type with high reliability, particularly a vehicle surroundings monitoring apparatus capable of determining an object by distinguishing between a pedestrian and other objects among objects.